Alternating-current motor.



No. 832,724. PATENTED 001?. 9, 1906. P. EIOHBERG.

ALTERNATING CURRENT MOTOR APPLICATION FILED JAN.12,.1906.

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Withesses- Inventor: M 2

Friedrich .Eichberg.

No. 832,724. PATENTED OCT. 9, 1906. P. BIOHBERG. ALTERNATING CURRENT MOTOR.

APPLICATION FILED JAN.12.190 5.

' 2 SHEETS-SHEET 24 Witnesses Inventor jjfl Friedrich Eichberg.

UNITED sTArns PATENT OFFICE.

FRIEDRICH EIOHBERG, OF BERLIN GERMANY, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented Oct. 9, 1906.

Application filed January 12,1905. Serial No. 240,880.

To all whmn it may concern:

Be it known that I, FRIEDRICH EICHBERG, a subject of the Emperor of Austria-Hungary, residing at Berlin, in the Empire of Germany, have invented certain new and useful Improvements in Alternating-Current Motors, of which the following is a specification.

My invention relates to the control of alternating-current motors of the ,commutator type; and it consists in a modification of the invention disclosed in a former ap lication of Gabriel Winter and myself, erial No. 146,692, filed March 7, 1903. In the former application we disclosed a form of alternating-current motor having three windings, one of which maybe termed the inducing-winding, sup lied with single-phase alternatingcurrent, t e second relatively movable to the first and in inductive relation thereto, which may be called the induced winding, and the third, which may be called the ma etizing-winding,- supplied with current om the secondar -'of a series transformer the primary of w 'ch is in series with one of the first two windings. The magnetizing-winding is arranged to produce a magnetization atan angle to that of the other two windin s, which, coacting with the currents of t e other two windings, produces the motor torque. Either the induced or inducing v winding may be stationary, and the the magnetizing-winding may be laced on the stator v or rotor and combined with one of the other windings or independent therefrom.

My present invention consists in connecting the magnetizing-winding to the source and supplying the inducing-winding from the secondary of a transformer the primary of which is in series with the magnetizing-winding.

My invention will best be understood by reference to the following drawings, in which I Figure 1 shows a diagram of connections. Fig. 2 shows diagrammatically my invention applied to the control of an alternatin -current motor of the commutator type, an Figs. 3, 4, and 5 show modifications of the arrangement of the motor-windings.

In Fig. l, C represents the magnetizingwinding,'connected to a suitable source of current. Arepresents the inducin -winding, displaced ninet degrees from C an l connected to the secon ary of the transformer T, the

primary of which is in series with the magnet izing-winding C. B represents the induced vwinding, WhlOh in this case is shown as the rotor provided with the brushes b I), connected to short-circuit the winding on the line of magnetization produced by the inducingwinding. S represents a switch by means of which the ratio of the transformer T may be varied so as to control the motor torque in a manner that has been heretofore ex lained in my former application. As has een said heretofore, the Winding C may be placed upon either stator or rotor and maybe com-' bined with the induced or inducing winding or may be independent therefrom.

In Fig. 2 the magnetizing winding is laced on the rotor and combined with the induced winding, the winding B in this figure performing the functions of both magnetizing-windin and induced winding. For this purpose it is rovided with two sets of commutator-brus es, one set b I) being connected to the source of current through the primary of transformer T, the portions of the rotor-winding between these brushes acting as the magnetizing-winding. The-second set of brushes b b short-circuit the motor on the line of magnetization produced by the statorwinding A, and the portions of the rotor-winding between these winding. The inducing-winding, which is shown as the statorewinding, is connected, as before, to the secondary of the series transformer T. The number of turns of either primary or secondary of transformer T may varied, and the two arrangements are shown in Figs. 1 and 2.

winding Cas a separate windin on the stator.

brushes act as the induced.

The connections of the severaI windin s are I the same as heretofore described. In Fig. 4 I have shown the magnetizing-winding C as a separate. winding on the rotor, provided with a separate commutator c. The connections are the same as in the preceding figures. In Fig. 5 I have shown the magnetizingwinding combined with the inducing-win ing on the stator, the connections remaining the same.

Although for the sake of simplicity I have shown my invention a plied to a motor hav- Gramme-ring win mgs on both members, it will be understood that my invention is appliable w any motor having the weileknown formed by the same coils which are also em' type of windingon either. member. It will be understood that it is entirely immaterial for the purposes of my invention whether the magnetizing-winding is formed entirely separate from the inducing and induced windings, as in Figs. 3 and 4, or-whether'it is ployed for either induced or inducing windmg, as in Figs. 2 andJ5. Consequently, although-for the sakepf convenience I employ the terms magnetizing-winding, inducing'w inding,-and induced winding in the appended claims, I desire it to be understood that I do not limit myself to a magnetizin winding independent of the other two .win ings, but include a magnetizing-winding formed from the same coils which also serve.

for'mducin or induced winding.

What I c aim as new, and desire to secure by Letters Patent of the United States, is

1. Inan alternating-current motor of the commutator type, a winding supplied with.

alternating current, a transformer having its rimary series with said winding, a secon winding connected to the secondary-of said transformer and arranged to produce a magnetization at an angle to that of the first winding, and a winding'short-circuited on etization of the second Windthe line of ma ing and mova le relatively thereto.

2. In analternating-current "motor of the commutator type, a winding sup lied with alternating current, a transformer iaving its primary in series with said winding, a second winding connected to the secondary of said transformer, and arranged to produce a mag' netization at an angle to that of the first, a windingshort-circuited on the line of mag-' netization of the second winding-and movable relatively thereto, and means for varying the ratio of transformation of said transformer.

3. In an alternating-current motor of the commutator type, a magnetizing-winding connected to a source of current, a transformer having its primary in series therewith, an inducing-winding dis 'lacedfrom the first winding and connecte to the. secondary of said transformer, and a short-circuited winding in inductive relation to the inducing-windmg and relatively movable thereto. I 3

4. In an alternating-current motor of the commutator type, a magnetizing-winding connected to -a source of current, a transformer having .its primaryin series therewith, an inducing-winding dis laced from the first winding and connecte to the secondary of said transformer, a short-circuited induced winding in inductive relation to the inducing-Winding and relatively movable thereto, and means for varying the ratio of transformation of said transformer.

5. In an alternating-current motor, a rotor- 5 es connected to a source of current, a

wmdin provided with a commutator,-a set of brush transformer having its primary in series Withsaid brushes, a second set of brushes short circuiting the rotor-winding on a line displaced from the first set, and a stator-windmg co'nnectedto the secondary of said transformer and arran ed to produce a magnetiza tion on the line 0 the second set of brushes;

6., In an alternating-current motor, a 'rotor winding provided with a commutator, av set of brushes connected to a source of current, a

transformer havmg its primary in series with said brushes, a second set of brushes shortoircuiting the rotor-winding on a line displaced from the first set, a stator-winding connected to the secondary ,of said transformer and arranged to produce a magnetization on the line of the second set of brushes,

and means for varying the ratio of transformatlon of sald transformer. Y

7. In an alternatmg-curre'nt motor, a rotor-' winding provided with a commutator, a set of brushes connected to a source of current, a transformer having its primary in series with said brushes, a stator-winding connected to the secondary of said transformer and arran ed vto produce a magnetization at an ange to that produced by. the current through the rotor-brushes, and means for short-circuiting the rotor-winding on the line of ma netization of the stator-winding. v, v 8. 11 an alternating-current motor, a rotorwindin provided with a commutator, a set of brus es connected to a source of current, a transformer having its primary in series with said brushes, a stator-winding connected to the secondary of said transformer and arranged to produce a magnetization at an angle to that produced by the current through v the rotor-brushes, means for shortcircuiting the rotor-winding on the line of magnetization of said statorwindin and means for varying the ratio of trans .ormation of said transformer.

In witness whereof I have hereunto set my hand this 21st day of December, 1904.

FRIEDRICH EICHBERG.

Witnesses:

HENRY. HAsPER, WOLDEMAR HAUPT.. 

